Steering mechanism for tractors.



W. H. WASHBURN STEERING MECHANISM FOR TRACTORS. APPucATioN FILED MAY 2, m3`

1,171,570, Pm-mwa Feb. 15, w16.

WILLIAM H. WASHBURN, 0F PORTLAND, OREGON.

STEERING MECHAISM FOR TRACTOES.

Application led May 2, 1913,

To allie/'10m it may conce-m Be it known that I, WILLIAM H. WASH- UnN, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Improvements in Steering Mechanism for Tractors, of which the following is a. specification.

My'invention relates to an improvement in steering mechanism for tractors Phaving an endless chain type of tread.

The object of this invention is to control and distribute the regular and nonvariable speed of gears, linkbelt or other positive means of transmission of the propelling power of a tractor so that the relative speeds of the two sides of the tractor may be changed to any rate desired in order to accurately steer the machine. I accomplish these and other objects by means of the structure illustrated in the accompanying drawing, in which the figure shows a plan view of a machine embodying my invention.

Referring to the drawings in detail, 1,. designates the frame, Work of a. tractor mounted upon suitable drive wheels 2 and 2a. at one end of the machine, and upon similarly formed idlers at the other, said wheels at each side of tliemachine bein mounted to travel in a chaitreadbelt 3.

Upon what may be termed the4 front end of the frame, is located the source of power, or engine 4, supplying powerthrough the shaft 5, on the rear end of which is a bevel pinion f5 meshing with the bevel gear 7 fixed upon the shaft 8, upon which the wheel 9 is fixed.V From the'sprockett' 9 a sprocket chain l1 leads to and operates upon the sprocket wheel 1() fixed upon the jack shaft 12; and upon this shaft is fixed a sprocket 13 carrying a chain 15 driving the differential gear 1.4, one side of which is fixed upon the axle 16 and the other side of which is fixed upon the sleeve 26. This axle carries the drive `wheels 2 and 2B.

Upon the rear end of engine shaft 5 is fixed the friction disk 17 against which the friction wheel`18. fitted with a feather upon shaft 19, bears. This'shaft is adjustable in its position by means of screw bolts 20, and the pressure of the Wheel 18 upon the disk 17 is controlied by means of lever 20a, which moves the base 20", through the rod 20s.

Upon the shaft 19 is fixed a pinion 21 meshing with a spur gear 22 fixed upon the Specification of Letters Patent.

Patented Feb. 15, i 916.

serial No. 765,081.

-jack shaft 23. This shaft in turn carries a sprocket Wheel 24 upon which is carried the sprocket chain 27 driving sprocket wheel 25 fixed on the axle 16.

Upon the application of power through the shafts 5, 8 and 12, the drive wheels 2 and 2a will be moved to propel the machine.. If they both move at the same rate of speed. the machine will advance in a straight line. But when it is designed to change direction` it is necessary to vary the relative rate of speed, which is accomplished as follows:

Should it be desired to turn the machine to the right. it Vwill be necessary to increase the speed of wheel 2l above that of whe Bv operating the lever 28, working tno groove 2f) formed in the hub of the friction wheel, b v means of rod 30, said friction Y wheel will he thrown toward the rin: of the disk 17. which will 'acceierac the motion of the friction wheel, and through it and the intervening mechanism. the drive wheel 2" carried on the axle 1G. The motion of hive wheel2 will be correspondingly retarded through the differential By reversing the directif/n of rod 30 the friction wheel wiil be carried toward the center'of disk 17 retarding its motion and g'. consequently retarding the motion of drive wheel 2, and thereby turning the machine to the left. These results have heretofore been accomplished by means of a steering wheel'at the front and placing the mechanism at the interior is a great economy in space, a needed improvernent in api'iearance and it adds much to the efficiency of the machine.

Having now described nrv invention what I claim as new, is

1. In a device of the cir ractex" described. an engine shaft, a drive. snaft mounted :uljacent thereto, a sleeve upon one end there of, a differential gear connecting the sleeve and shaft. a drive wheei fixed upon the sleeve and another upon said sh ft, mechaa nism operatively' connecting the r i with the differentialvgear, a fr fixed upon the rear end of the engine a friction wheel adapted to hear tin er mechanism fixed upon the drive shaft operatively connected with the friction whcei. and means for shifting the friction wheel to controlXthe relative speed of the drive wheels.

2. In a device of the class referred-to, in combination with two main drive or trac- -mechanism to' said differential for driving both parts of said axle together, an auxiliary driving connection 'imm said power furnishing mechanism to one part of said axle, and means for varying the speed of 4said auxiliary drive, whereby the speed and direction of one part ofsaid axle can lhe coil- ,trolled independently of the 'other part ci said axle and indepl ndently offthe/positivev drive to saiddiilerentiel.

3. In a device of the -class refer-red to,\` in combination With'two' main drive or trad-4 tion wheels, a. two part a-Xle therefor, a differential connecting the lparts thereof, power furnishing mechanism, positive driving connections from said power furnishing mecha-v nism to said differential for driving Aboth parts of saidaxle together, an auxiliary .friction drive connection fromsaidpower furnishing mechanism to one part of said ax'le and vmeans for varying the speed ofsaid rict/ion drive whereby to drive one part of said axle faster or slower through said fric-V ti'on drive independently of said positive drive to said differential, for steering purposes, substantially as described.

4. In a. device of the character described the combination of a drive shaft, a drive wheel mounted rigidly on one end of the drive sl1aft,'a sleeve revolubly mounted on the other end of the drive shaft, a drive 'wheel 'irigidly mounted on the outerV end of the sleeve, a. differential/gear connecting theinner end-of the sleeve'with the'drive Shaft means lor drivin theI differential gearat a. fixed ratio with t 1e en ine speed and means for driving the drive s aft at varia-ble' speed ratios as compared with theenginespeed.

`In testimony whereofdlfaflix'my signature in presence oftwo witnesses. VF

WILLIAM VASHBURN. Witnesses:

EDWIN E. HECKBERT, HAz'eL A. RMs'rkoNo, 

